Decorative resin molded articles in which a decorative sheet is laminated on the surface of a resin molded article have been heretofore used in vehicle interior and exterior components, building interior materials, cases for home electric appliances, and the like. In production of such a decorative resin molded article, for example, a molding method is used in which a decorative sheet given a design beforehand is integrated with a resin by injection molding. Typical examples of the molding method include an insert molding method in which a decorative sheet is molded into a three-dimensional shape beforehand by a vacuum molding die, the decorative sheet is inserted into an injection molding die, and a fluidized resin is injected into the die to integrate the resin with the decorative sheet, and an injection molding simultaneous decorating method in which a decorative sheet inserted into a die in injection molding is integrated with a molten resin injected into a cavity.
As a method for imparting design property such as an irregularity feeling, a stereoscopic feeling or a depth feeling on the surface of such a decorative resin molded article, an attempt has been made to print a pattern on the back surface of a base material sheet, and form an irregularity shape on the surface of the base material sheet by embossing (stamping). However, when an irregularity shape is formed on the surface by embossing, the irregularity shape may be restored to a flat surface under the action of heat and stress during injection molding or preceding premolding (vacuum molding). Such an irregularity shape is formed of a thermoplastic resin, and therefore may be easily lost or damaged due to abrasion.
As a decorative sheet with an irregularity shape formed thereon by a method different from embossing, for example, Patent Document 1 discloses an irregularity insert sheet including a base material sheet, one surface of which is provided with at least a fine irregularity layer having a thickness of 2 μm or more and a pensile hardness of HB or more as measured by the test method specified in the Japanese Industrial Standards (JIS) K5400. For example, Patent Document 2 proposes that when the arrangement and size of convex area portions which form an irregularity shape on a surface of a molding decorative film are defined such that the total area of the convex area portions constitutes 45% or less of the area of the whole surface of a base material sheet, and the area of one convex area portion is 2 mm2 or less, the problem of occurrence of cracking in the convex area portions is improved.